Files
MoFin/venv/lib/python3.12/site-packages/nltk/test/unit/test_cfg2chomsky.py
T
知微 fa45d8aa5f fix: 小果地址统一node122(兼容LAN+EasyTier)
- health_checklist.json: 192.168.1.122→node122
- ocr_client.py: docstring IP→node122
- docs/market-data-requirements.md: IP→node122
- 所有API调用通过ProxyHandler({})绕过系统代理
  Privoxy对node122:18003返回500,直连正常
2026-06-30 02:56:35 +08:00

50 lines
1.6 KiB
Python

import unittest
import nltk
from nltk.grammar import CFG
class ChomskyNormalFormForCFGTest(unittest.TestCase):
def test_simple(self):
grammar = CFG.fromstring(
"""
S -> NP VP
PP -> P NP
NP -> Det N | NP PP P
VP -> V NP | VP PP
VP -> Det
Det -> 'a' | 'the'
N -> 'dog' | 'cat'
V -> 'chased' | 'sat'
P -> 'on' | 'in'
"""
)
self.assertFalse(grammar.is_flexible_chomsky_normal_form())
self.assertFalse(grammar.is_chomsky_normal_form())
grammar = grammar.chomsky_normal_form(flexible=True)
self.assertTrue(grammar.is_flexible_chomsky_normal_form())
self.assertFalse(grammar.is_chomsky_normal_form())
grammar2 = CFG.fromstring(
"""
S -> NP VP
NP -> VP N P
VP -> P
N -> 'dog' | 'cat'
P -> 'on' | 'in'
"""
)
self.assertFalse(grammar2.is_flexible_chomsky_normal_form())
self.assertFalse(grammar2.is_chomsky_normal_form())
grammar2 = grammar2.chomsky_normal_form()
self.assertTrue(grammar2.is_flexible_chomsky_normal_form())
self.assertTrue(grammar2.is_chomsky_normal_form())
def test_complex(self):
grammar = nltk.data.load("grammars/large_grammars/atis.cfg")
self.assertFalse(grammar.is_flexible_chomsky_normal_form())
self.assertFalse(grammar.is_chomsky_normal_form())
grammar = grammar.chomsky_normal_form(flexible=True)
self.assertTrue(grammar.is_flexible_chomsky_normal_form())
self.assertFalse(grammar.is_chomsky_normal_form())